John York served as a missionary in Nigeria, Malawi and Togo for 23 years. For sixteen of those years, he directed three Assemblies of God Bible colleges in Nigeria where the AG burgeoned from about 150,000 to well over two million.

In 1990, John became the director of Africa Theological Training Service, a support ministry involving extensive travel among over 200 colleges and training programs across Africa, serving 14,000 students. Dr York authored several book and articles on missions training.

Brother York died in Houston, Texas on December 22, 2005.